Continuity for a function with two independent variables

 

 

 

In a Nut Shell:  Continuity means that if the point (x,y) changes by a small amount then

the value of  f(x,y ) also changes by a small amount.  It implies that the surface, f(x,y),

contains no holes or breaks.

 

 

The formal definition of continuity:

 

A function of two variables, x and y, is continuous at  (a,b)  if

 

                                       lim         f(x,y) =  f(a,b)

                              (x,y) →(a,b)

 

 

f(x,y) is continuous at every point (a,b) in D, its domain.

 

 

Types of continuous functions:

 

All polynomials in x and y are continuous on the plane.

 

The sums, differences, products, and quotients of continuous functions are continuous.

 

A rational function is a ratio of polynomials.  So any rational function is continuous

on its domain, D.

 

 

 

             

Click here for examples.

 




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